/Engine/Plugins/Editor/EditorScriptingUtilities/Source/EditorScriptingUtilities/Public/EditorLevelLibrary.h
Find the references of the mesh MeshToBeReplaced on all the MeshComponents of all the Actors provided and replace it by NewMesh.
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, Category="Editor Scripting | Dataprep", Meta=(DeprecatedFunction, DeprecationMessage="The Editor Scripting Utilities Plugin is deprecated - Use the function in Static Mesh Editor Subsystem")) static void ReplaceMeshComponentsMeshesOnActors ( const [TArray](API\Runtime\Core\Containers\TArray)< class [AActor](API\Runtime\Engine\GameFramework\AActor) * > & Actors, class [UStaticMesh](API\Runtime\Engine\Engine\UStaticMesh) * MeshToBeReplaced, class [UStaticMesh](API\Runtime\Engine\Engine\UStaticMesh) * NewMesh )